Process for dyeing textile materials from organic solvent media

ABSTRACT

THE PRESENT INVENTION CONCERNS A METHOD OF DYEING TEXTILE FIBERS, PARTICULARLY IN THEIR WOVEN, YARN OR LOOSE MAT STATE, EMPLOYING DYESTUFFS DISSOLVED OR DISPERSED IN ORGANIC SOLVENTS, PARTICULARLY CHLORINATED HYDROCARBON SOLVENTS, FOR FIXING THE DYESTUFF INTO THE FIBER DURING THE PROCESS AND FOR RECOVERING SUBSTANTIALLY COMPLETELY THE SOLVENT FROM THE DYED FABRIC. THE TECHNIQUE OF THE PRESENT INVENTION EMPLOYS COMPOSITIONS COMPRISING HYDROPHOBIC ORGANIC SOLVENTS ALONE AND/OR IN ADMIXTURE WITH COSOLVENTS, SWELLING AGENTS AND FIXATIVES WHICH ARE COMPATIBLE WITH THE SOLVENT AND THE SOLUBLE AND/OR DISPERSIBLE ORGANIC DYESTUFFS. THE NOVEL METHOD COMPRISES APPLYING SOLVENT COMPOSITIONS OF DYESTUFFS TO TEXTILES, DIFFUSING   AND FIXING THE DYESTUFF INTO THE TEXTILE FIBERS WHILE MAINTAINING THE TEXTILE FIBER IN A ZONE FILLED WITH THE VAPORS OF A SOLVENT BOILING BETWEEN ABOUT 40*C. AND THE SOFTENING POINT OF THE FIBER, AND RECOVERING THE SOLVENT EITHER CONTEMPORANEOUSULY WITH SAID FIXATION OR IN A RINSE STEP FOLLOWING SAID FIXATION.

June 6, 1972 s. BERGMAN ErAL 3,667,898

PROCESS FOR DYEING TEXTILE MATERIALS FROM ORGANIC SOLVENT MEDIA Fi ledMay 26, 1969 5 Sheets-Sheet 1 INVENTORS. 1 Sy/ves/er fiery/n 0/) BY R055R. Dawson 9 TOR/VEY June 6, 1972 s. BERGMAN ETAL 3,667,898

PROCESS FOR DYEING TEXTILE MATERIALS FROM ORGANIC SOLVENT MEDIA FiledMay 26, 1969 3 Sheets-Shoot 2 INVENTORS. dy/ves /er 5 erg/nan BY R055 R.DOM/$0? HTTORNEY June 6, 1972 BERGMAN ETAL 3,667,898

PROCESS FOR DYEING TEXTILE MATERIALS FROM ORGANIC SOLVENT MEDIA FiledMay 26, 1969 5 Sheets-Shut 5 INVENTORS. Q Qy/vesver ergman Q BY R055 R.Dawson \Q Q 0 o United States Patent Office Patented June 6, 19723,667,898 PROCESS FOR DYEING TEXTILE MATERIALS FROM ORGANIC SOLVENTMEDIA Sylvester Bergman, Midland, Micln, and Ross R. Dawson,

Buifalo, N.Y., assignors to The Dow Chemical Company, Midland, Mich.

Continuation-impart of application Ser. No. 670,433, Sept. 25, 1967.This application May 26, 1969, Ser. No. 827,620

Int. Cl. D06p 1/68 U.S. Cl. 8-94 19 Claims ABSTRACT OF THE DISCLOSUREThe present invention concerns a method for dyeing textile fibers,particularly in their woven, yarn or loose mat state, employingdyestuffs dissolved or dispersed in organic solvents, particularlychlorinated hydrocarbon solvents, for fixing the dyestufi into the fiberduring the process and for recovering substantially completely thesolvent from the dyed fabric. The technique of the present inventionemploys compositions comprising hydrophobic organic solvents aloneand/or in admixture with cosolvents, swelling agents and fixatives whichare compatible with the solvent and the soluble and/or dispersibleorganic dyestuffs. The novel method comprises applying solventcompositions of dyestufis to textiles, diffusing and fixing the dyestufiinto the textile fibers while maintaining the textile fiber in a zonefilled with the vapors of a solvent boiling between about 40 C. and thesoftening point of the fiber, and recovering the solvent eithercontemporaneosuly with said fixation or in a rinse step following saidfixation.

CROSS REFERENCE TO RELATED APPLICATIONS This application is acontinuation-in-part of our earlier filed application Ser. No. 670,433,filed Sept, 25, 1967, now abandoned.

BACKGROUND OF INVENTION Dyeing of textile materials, especiallycontinuous rapid dyeing of such materials, often presents difficultiesarising from the rate of diffusion of, and aflinity between dyestufi andfiber in an aqueous medium. Variations are noted among the severalfibers, the dyestuffs, and the dyeing media.

Many of these difiiculties can be overcome by employploying specialdyeing techniques to control diffusion of dye into the material. Forexample, linear polyester fibers can be dyed with dispersed dyes byapplication of superatmospheric pressure (pressure dyeing) or morerapidly and effectively by application of extreme temperatures, above200 C. (Thermosol Process). The rapidity of the latter dyeing methodmakes it particularly Well adapted to continuous dyeing of polyesterfiber. However, the

foregoing procedures have the disadvantage of requiring complex andcostly dyeing equipment.

Further, it has been suggested to dye polyester fibers with disperseddyestuffs in the presence of an organic solvent as a carrier, in aneffort to shorten the time for dyeing and lower the temperature. Thecontention advanced being that the organic solvent swells the fiber oracts to decrease the intermolecular attraction forces of the fibermolecules and thus accelerates the dyeing. Use of such carrriers assolvents for the dye, a non-aqueous system, is generally not feasiblecommercially due to the large amounts of relatively expensive carrierrequired and lack of suitable recovery technology. On the other hand,use of a relatively small charge of such carriers in an aqueous bathcontaining a dispersed dye gives a relatively Weak dyeing or requires anexcessively long dyeing time. Some of the disadvantages of the foregoingprocedures have been overcome by dyeing linear polyester fibers in adyebath composed of an aqueous emulsion of a solvent solution of dyestabilized by an emulsifying agent (Peirent et al., American DyestutfReporter, 49, 72 (1960)). This process, commonly referred to as theSolvent Emulsion Technique, requires only a relatively small quantity ofcostly solvent, since the external aqueous phase of the emulsion acts asa vehicle to distribute the small amount of dye-carrier solution amongthe fibers.

Numerous carrier compositions have been developed by the prior art butthese, in general, have objectionable features which restrict their usein carrier dyeing of polyester fibers and especially as dye solvents indyeing according to the Solvent Emulsion Technique. Some Wellknowneffective carriers, e.g., diand trichlorobenzene are relatively poorsolvents for dispersed dyestuffs. Because of the low solubility of thesedyes in such carriers, large amounts of these carriers must be employedin Solvent Emulsion dyeing to dissolve the quantity of dyestufi requiredfor deep dyeings. Inasmuch as dye absorption by a polyester fiberdiminishes as the concentration of carrier in the Solvent Emulsiondyebath passes above a certain level, the depth of shade obtainable isseverely limited. Moreover, the high concentrations of carrier requiredare prohibitively costly, adversely afiect the levelness of the .dyeingperiods required for continuous dyeing were achieved only attemperatures of to 200 C.

Prolonged treatment in the dyebath is obviously unsuitable forcontinuous dyeing (for instance, dyeing of piece goods) and is costlyfrom the viewpoint of time and energy consumed, while the higher dyeingtemperatures have a degrading elfect both on the dye and the fiber.

Attempts to improve the dyeing of the aforementioned fiber withassistants and carriers often give unsatisfactory results, eitherthrough altering the properties of the fibers or by degrading thefastness of the dyes. Several processes using non-aqueous solvent mediahave been proposed for the purpose of decreasing the dyeing time, butthe temperatures required in these process are high, in the range of 130to 200 C. At these temperatures, many dispersed dyes decompose and ithas been necessary to add a dye stabilizer to the dyebath. Also, thesemethods introduce the problem and cost of removing the solvent from thedyed fiber.

According to US. Pat. No. 3,098,691, the aforenoted problems wereeliminated and the dyeing of polyester fiber with water-insoluble dyesfree of ionogenic substituents was elfected neatly and rapidly byemploying a dioxane dyebath at a temperature between 80 to 105 C.(preferably 95 to 100 C.) for a short period (usually less thanminutes), whereupon the fiber is removed from the dyebath, rinsed withWater and dried.

An improvement in the known dyeing process is described in US. Pat. No.2,999,002 in which textile materials are padded with aqueous suspensionsof dispersed dyes and dried and thereafter treated with vapors of achlorinated aliphatic hydrocarbon, notably trichloroethylene, and thenrinsed in hot water and scoured with soap.

BRIEF DESCRIPTION OF INVENTION It has now been found that a fibrousmaterial, either naturally occurring or man-made, can be dyed bytreating the fibrous material whether it be in its woven, loose mat I oryarn state with a dye formulation (which may contain water) dissolved ordispersed in a vehicle consisting essentially of a volatile organicsolvent; dilfusing the dyestutf into the fibrous material;simultaneously removing the solvent from the fibrous material and fixingthe dyestulf into the fibers while maintaining the fibrous material in azone composed primarily of the vapors, which may be superheated, of thesolvent. Alternatively, the dyestulf is infused and fixed in the vaporzone of a solvent, the dyestufi solvent removed by scouring and thescouring liquor removed by introduction into a zone of vapors of therinse liquor which may be superheated.

Commercially acceptable dyed fabrics have been obtained when thedyestuff is dissolved or dispersed in a volatile organic solvent havinga boiling point above about C. but below the softening point of thefibrous material and below the decomposition point of the dyestulf. Itmay be advantageous to employ as a part of the dye formulation a fiberswelling agent which may be a cosolvent or a special agent. The processof the present invention can readily treat the fibrous material directlyfrom the loom or weaving without the usual clean-up or scouring toremove lubricants and the like, with a dye formulation, infuse thedyestuff into the fiber, remove the solvent and fix the dyestuff whenthe fibrous material, treated with the dye formulation, is maintained ina zone of the vapors of the solvent for from about 10 to about 180seconds, or longer. The vapor zone can conveniently be established byvarious means such as boiling solvent at the bottom of the zone,employing heated drums or cans within the vapor zone over which thefibrous material is passed, or the zone can be supplied with vapors,which may be superheated, from a source external of the zone. The escapeof vapors from the vapor zone is prevented by providing a vaporcondensing means which establishes the upper limit of the vapors andremoves vapor in excess of that required to fill said zone. Thecondensed vapors may be re-used in the dye formulations and/or togenerate the vapor in said zone. The fiber, after fixation of the dyeand removal of excess solvent, may be rinsed to remove undesirablematerials remaining after dyeing, such as dyeing assistants, etc., anddried in a vapor zone of a solvent of the character aforedescribed.

Alternatively, the process of the present invention can treat a fibrousmaterial with a dye formulation which contains a solvent vehicle whichhas a boiling point above the boiling point of the volatile organicsolvents. When such a solvent is employed, either as the principal or asthe co-solvent, the steps to produce a satisfactorily dyed fiber consistof treating the fiber with the dye formulation, passing the wetted fiberinto a zone of vapors of a solvent which has a boiling point betweenabout 40 C. and the softening point of the fiber to diffuse the dye intothe fiber. The so-treated fiber is then scoured in a solvent to removethe residual higher boiling solvent. The scouring solvent having aboiling point between about 40 C. and the softening point of the fiber,remaining on the fiber, is removed by passing the fiber into the vapors,preferably superheated, of a" solvent having a boiling point betweenabout 40 C. and the softening point of the fiber. The higher boilingsolvent is of course recoverable from the scouring solvent.

It is to be understood that substantially any fibrous material,commercially available, whether natural or manmade, or blends thereof,can be dyed in accordance with the present invention. Thus, thenaturally-occurring fiber (such as wool and cotton) and the syntheticfibers (such as the polyarnides, the polyesters, the cellulose acetates,regenerated cellulose, the acrylics, polypropylenes and polyethylenes)can be dyed, as well as blends of these fibers, with a wide range oftypical dyestuffs.

Exemplary of the dyes and suitable formulations for use in the presentinvention are adequately disclosed below.

Dispersed dye is intended to encompass the class of substantiallywater-insoluble dyes, this class having been originally introduced forthe dyeing of cellulose acetate and usually applied from fine aqueoussuspension.

C.I. Disperse Yellow 1 (C.I. 10345) C.I. Disperse Yellow 3 (C.I. 11855)C.I. Disperse Red 11 (C.I. 62015) C.I. Disperse Blue 26 (C.I. 63305 C.I.Disperse Blue 7 (C.I. 62500) C.I. Disperse Yellow (C.I.)

C.I. Dispersel Yellow 9 (C.I. 10375) C.I. Disperse Orange 11 (C.I.60700) C.I. Disperse Red 19 (C.I. 11130) C.I. Dispersed Red 1 (C.I.11110) C.I. Disperse Red 13 (C.I. 11115) C.I. Dispersed Red 3 (C.I.)

C.I. Disperse Blue 14 (C.I. 61500) C.I. Disperse Blue 19 (C.I. 61110)C.I. Disperse Blue 27 (C.I.)

C.I. Disperse Red 35 (C.I.)

C.I. Disperse Yellow 37 (C.I.)

C.I. Basic Orange 21 (C.I.)

C.I. Direct Red 31 (C.I. 29100) C.I. Acid Orange 86 (C.I.)

C.I. Acid Blue 40 (CI. 62125) C.I. Acid Blue 25 (C.I. 62055 C.I. AcidRed 209 (C.I.)

C.I. Acid Red 114 (CI. 23635) C.I. Basic Blue 21 (C.I.)

C.I. Basic Green 4 (C.I. 42000) C.I. Basic Red 13 (C.I. 48015 C.I. BasieViolet l4 (C.I. 42510) C.I. Basic Yellow 11 (C.I. 48055) C.I. DirectYellow 12 (C.I. 24895 C.I. Direct Green 12 (C.I. 30290) C.I. Direct Blue55 (C.I. 27940) Colour Index-The Society of Dyers and Colourists, TheAmerican Association of Textile Chemists and Colorists, 2nd ed., 1957.

Although the above classes of dyes, e.g.,, dispersed andsolvent-soluble, are a preferred class, other known dyestuffs such asacid, basic metal containing and metalizable dyestuffs, can be employedequally well when the organic solvent is a chlorinated solvent, and/orthe cosolvent employed is, for example, a dialkyl formamide, dialkylacetamide, dialkyl sulphoxide, a glycol, a polyol, an alcohol or estersand ethers thereof. The dyestufi is employed in from about 0.1 to about10 parts by weight and preferably from about 0.1 to about parts byweight, per 100 parts of solution.

In many instances, it is advantageous to employ fiber swelling orinfusing agents to aid in the introduction and absorption of thedyestuff into the fiber as taught in the foregoing copending applicationof Ross R. Dawson. When such agents are deemed necessary as, forexample, in dyeing the synthetic fibers, such agents which act to swellthe fibers as ethylene carbonate and/or dialkyl acylamides canconveniently be employed. The fiber swelling or infusing agent isemployed in amounts up to 0.1 part on the weight of fiber (OWF)equivalent up to parts by weight of agent per 100 parts by weight of dyeformulation. Preferably this agent is employed in amounts of 0.01 toabout 0.05 OWF (equivalent to about 0.1 to 5 parts per 100 parts byweight of dye liquor).

The organic solvents which can be. employed in accordance with thepresent invention are the aliphatic hydrocarbons, the aromatichydrocarbons, and the chlorinated, brominated and fluorinated and mixedhologenated lower aliphatic hydrocarbons having from 1 to 4 carbonatoms, chlorinated aromatic hydrocarbons, lower alcohols, glycols andpolyols, esters and ethers thereof and blends thereof, said polyolshaving average molecular weights from about 62 to 5000, the dialkylformamides, dialkyl acetamides and dialkyl sulfamides, such as dimethylformamide, dimethyl acetamide, and dimethyl sulfoxide, and mixturesthereof, both within the same class and among the classes. Thesesolvents are liquid at room temperature and some will vaporize at aboveabout 40 C. to just below the softening temperature of the fiber beingdyed, the others, the higher boiling solvents, those nonvolatile attemperatures at or above fiber softening temperature, are removable inthe scouring step. The pre ferred class of solvents are the aryl andalkaryl hydrocarbons, halogenated aromatic hydrocarbons, the petroleumnaphthas, and the C to C chlorinated and fluorinated saturated aliphaticand olefinic hydrocarbons. Representative of the preferred class ofsolvents are benzene, toluene, trichlorobenzene, naphtha, carbontetrachloride, methylene chloride, 1,1,l-trichloroethane,trichloroethylene, tetrachloroethylene (perchloroethylene), hexane, andmixtures of two or more of these. The solvent is employed in quantitiessufiicient to dissolve or disperse the dyestuff, generally 90 to 99parts by weight based on the total weight of the composition beingpreferred.

Included among these solvents are materials which in certain instancesfacilitate the dispersion, solution and/or infusion of the dyestulf.These materials are hereafter known as co-solvents. The materials whichare suitable co-solvents are the alcohols, glycols, polyols (saidglycols and polyols having an average molecular weight of from 62 toabout 5000), the esters and ethers thereof, the aromatic and halogenatedaromatic hydrocarbons, and the dialkyl formamides. While theseco-solvents are also good principal solvents, they are more economicallyand advantageously employed as co-solvents. When so employed they areconveniently employed in amounts from 1 to 50 parts by weight based onthe total composition. The cosolvents are either removed during primarysolvent removal or in the scouring step which is generally employedalthough not critical if a co-solvent of high boiling character is notemployed.

Dyestuff compositions which have been found useful in accordance withthe present invention are those containing from about 0.001 to about 10parts by weight of a dyestuff, about 99 to about 80 parts by weightorganic solvent (which may contain 0 to about 50 parts by weight of aco-solvent) 0 to about 10 parts by weight swelling or infusing agent allbased on 100 parts by weight of dyestuff composition. The preferredcompositions contain about 0.1 to about 5 parts by weight of dyestuff,about to about parts solvent of which about 5 to about 10 parts is aco-solvent, and from about 0.0 to about 5 parts of swelling or infusingagent.

It is to be understood that other agents known to the dye industry andtextile industry can be added to the dye solution to achieve recognizedadvantages and properties such as leveling in the finished fiber ortextile Without departing from the spirit of the present invention.

It is to be further understood that dye formulations containing fromabout 2 to about 20%, preferably about 10% by weight water can also beemployed in accordance with the present invention.

It is to be further understood that the same precautions known to thoseskilled in the art of dyeing should be taken relative to relating dyesto fibers.

DETAILED DESCRIPTION OF INVENTION The method of the present inventioncomprises padding, spraying, dipping, flooding or otherwise applying adyestuff composition, which is a dye dissolved or dispersed in anorganic solvent, of the character aforedescribed, preferably achlorinated hydrocarbon solvent, onto a textile fabric, e.g., rug,carpet, upholstery fabric, thread, cloth or the like, and introducingthe thus wetted textile into a zone of vapors of a volatile organicsolvent, preferably the same solvent as employed in the dyestuifcomposition. While still within the zone of vapors, the textile issubjected to heat, introduced either by passing the textile over heatedrolls, using microwave heating or introducing vapors, preferablysuperheated, into the vapor zone to contact the textile, or both,sufficient to raise the temperature of the fibers above that of theboiling point of the solvent. Any one or a combination of two or moremethods may be employed. As a result of this operation, the solventpresent on the fibers, if boiling at or below the temperature applied,is volatilized. Further, during and simultaneously with the passage ofthe textile material through the vapor zone the dye is diffused andfixed into the fiber. Thereafter, the textile is brought out of thevapors into the ambient atmosphere if the solvent is volatilizable, ormay be scoured in a clean solvent, which is removed in like manner.

If it is advantageous to employ a solvent either as the principalsolvent or as a co-solvent which boils above the softening point of thefiber, the solvent of course will not be removed during passage throughthe vapor zone, It is thus essential, after diffusion and fixation, toscour the high boiling solvent from the fiber with a solvent boilingbelow the softening point of the fiber and then remove the lower boilingsolvent by passing the scoured fiber through a vapor zone of a likesolvent.

Following this general technique, the examples set out in detailillustrate the present invention both as regards the dyestuffcompositions and method which have been employed to successfully dyetextile fabrics and fibers.

A textile cloth woven from a natural fiber, e.g., mohair or a syntheticfiber, e.g., a polyester blend'or an acrylic blend, was passed through apadding device by which means a dyestuif-solvent composition wasintroduced onto and into the textile. The so-wetted textile was passedinto a zone filled with vapors of the solvent employed until fixation ofthe dyestulf had taken place and the textile was freed of solvent. Thenature of the textile, the bath composition, time periods, etc., aregiven in the table below. The apparatus employed to carry out theprocess of the present invention to obtain the data below is describedin the drawing and in particular detail in US. patent applications Ser.Nos. 505,520, filed Oct. 28, 1965, and 585,893, filed Oct. 11, 1966 bothnow abandoned, Method and Apparatus for Treating Fabric and the Like, byK. S. Surprenant, which description of apparatus and drawings areincorporated by reference into this description.

Dye Liquor, parts by weight total composition Dyestufi I (JosolventSolvent and/or Amt., dyeing Temp Time, Type of fiber Kind OWF 1 DyestufiAmt. Kind assistant sec.

Polyester. 0.1. disperse blue 27-..-- 0.5 0.5 89.5 perchloroethylene..-

} 1 1 4 Do.-. do 0. 5 50. 0 trlchloroethylene 5 37 45 Acrylic do 0. 6 0.5 69. 5 perchloroethylene.. 2-3 121 35 Polyester. do.. o. 5 o. 5 se 5'.--do 121 45 Nylon ()1. acid red #182. 0.2 0. 2 90 -.do o 2 i0 130 045. 0 RBY0ll. Direct red 8 0. 1 0. 1 0 hi hl m ylenen; J 5 130 5D 5 I445. 0 Mohair Basic yellow 13- 0.1 0.1 40. 0 -:;'..d0-... 28 145 50 8 I47 a 10. 0 Polyester. Dispersed violet #42 0. 8 0. 8 89. 2 do.... 1 Q 4143 60 l 0. 4 Acryllc Basic yellow l3... 0. 4 0. 4 85. 0 do 121 0 1 OWFdye based on weight of fabric. 2 Parts ethylene glycol phenyl ether. 3Dlmethyl formamlde. Ethylene carbonate. 6 Armjd O, a mixture ofstearoylamide 6%, oleylnmide 91%, linoylamlde 3.0%. 5 Water.

1 Alkylphenoxypolyethyleneoxyethanol (Igepal DM 5230) Ethylene glycolethyl ether.

Another apparatus suitable for use in accordance with the presentinvention is described in US. Pat. 3,408,748.

Another embodiment of an apparatus for carrying out the presentinvention, as illustrated in FIG. 1, a structure is provided havingthree distinct chambers, each associated with the others for passage ofa base material, e.g., floor covering, from the ambient environment intoand out of each chamber and return to the ambient environment. Thedescription of the embodiment of the apparatus of FIG. 1 will havespecific reference to its use to dye floor covering; however, it is tobe understood that change in size and line speeds may be made to enablethe dyeing of lighter weight fabrics.

FIG. 1 has been divided into four sections, the first section 10 beingthe dye applicator which is not a part of the present invention orapparatus since existing commercial dye applicators can be employed. Thesecond section .11 is the dye diffusion and fixation chamber. The thirdsection 12 is the rinse chamber and the fourth section 13 depicts thefinal drying section.

Dye diifusion and fixation section 11 The dye diffusion and fixationsection 11 comprises a chamber .14 having side walls 15 and 16, a bottom17 and a top 18. The bottom :17 has, as illustrated, a well 19 which isprovided with heating means 20. The heating means may be electrical,steam, or flame systems, commercially available and operative under theconditions here employed, e.g., nature of solvent to be heated, etc.

Along the side wall 15 is an opening 21 which is located near the upperextent of the side wall 15. This opening 21 provides ingress into theinterior of the chamber 14 of a base material 22, e.g., floor coveringto which a dye formulation has been applied. Located within the chamber14 extending peripherally around the interior walls at a point justbelow the opening 21 in side wall 15 is a series of coils 23 which serveas condensing surfaces (for vapors which are generated within chamber14. These coils 23 establish the upper extent of the vapor zone 27within chamber 14.

Located directly below said coils 23 is a trough 24 to collect thecondensate from coils 23. The trough 24 is in (fluid communication witha storage tank not shown and/ or the well 19 supplying liquidvaporizable solvent to the well 19 as well as solvent for preparation ofdye formulations.

The interior of the chamber 14 is provided with idler rolls 25 locatedin a manner to direct the base material 22 into chamber 14 in a path 26to maintain the base material 22 within the zone of vapors 27established 8 Ethofat C 15, coco acids esters of polyoxyethylene glycol.

between the condensing coils 23 and the bottom 17 of the chamber 14.Positioned along the path 26 of the base material 21 through zone 27 ofchamber 14 are a series of superheatcrs 2 8. These superheaters 2-8 areillustrated as steam heated finned radiators, although other means suchas electrical heaters, gas fired radiators and microwave generators aswell as provisions for introducing superheated vapors as shown in FIG. 2are suitable in their stead.

The location of the condensing coils 23 is such that above the vaporlevel 27a established thereby is a substantially vapor-free zone 29which is essentially quiescent in nature. This zone 29 extends acrossand above each of the other units 12 and 13.

A series of idler rolls 30 are located within unit 12 to direct material21 into chamber '31 which is the scour unit 12. Located within rinseunit 12, chamber 31 are a series of nozzles 32 which are connected to apressurized source of rinse liquid. The lower portion of chamber 31 isdesigned to hold a quantity of scouring liquid 33 suflicient to engulfthe base material 21 during its passage through chamber 31. The nozzlesare positioned in a manner such that their force is directed against thenormal flow of liquid down the base material thus offsetting to someextent the cii'ect of cascading created by liquid flowing downwardlyover the heavy nap of the floor covering causing the nap to bend withthe flow. The chamber 31 has been provided with a series of condensingcoils 34 to condense vapors which might be generated within chamber 33and a trough 35 to collect the condensed vapor thus preventing vaporsfrom escaping into zone 29. 1 7

Unit 13 is similar in construction to unit 11 but is somewhat of amirror image thereof. Unit 11 provides a means for removing scouringsolvent from the base material and recovering the so-remo'ved solvent.

oftentimes it will not be economical or desirable to employ radiators 28such as shown in FIG. 1. When such is not desired, it will be expedientto employ zones defined by plates traversing the path 26 of the fabricas illustrated in FIG. 2 at 22-8. When such is employed, the well 19 andits associated heating coils 20 may be dispensed with. When employingthe plates 228, it is of course necessary to provide a solvent vaporizer236 and a solvent vapor superheater 237.

Further, even the plates 228 illustrated in FIG. 2 are not alwaysessential. As shown in FIG. 3, a vaporizer 336 and superheater 337 aresupplied with liquid and vapors and open directly to the interior ofchamber 14.

Other modifications will become apparent to those skilled in the art.

The operation of the apparatus illustrated in the figures isself-evident and is readily seen to permit conducting the novel methodof dyeing hereinbefore described. The dyeing process of the presentinvention has been carried out employing a prototype of the apparatusdescribed in FIG. 1 on a laboratory scale with good results.

In the operation of the apparatus described hereinabove, the loss ofsolvent was about five (5%) percent of that introduced into theapparatus either in the dye formation or as vapor and/or scouringliquor.

It is to be understood that when scouring is not necessary to remove dyeassistants, etc., the rinse section 12 and the drying unit :13 need notbe employed. Thus one can dye a fabric satisfactorily in an apparatussuch as illustrated in FIG. 3.

Another embodiment of an apparatus for carrying out the presentinvention, as illustrated in FIG. 4, comprises a structure having threedistinct chambers, each associated with the others for passage of a basematerial, e.g., floor covering, from the ambient environment into andout of each chamber and return to the ambient environment. Thedescription of the embodiment of the apparatus of FIG. 4 will havespecific reference to its use to dye floor covering; however, it is tobe understood that change in size and line speeds may be made to enablethe dyeing of lighter weight fabrics.

FIG. 4 has been divided into four sections, the first section 410 beingthe dye applicator which is not a part of the present invention orapparatus since existing commercial dye applicators can be employed. Thesecond section 411 is the dye diffusion and fixation chamber. The thirdsection 412 is the rinse chamber and the fourth section 413 depicts thefinal drying section.

Dye difiusion and fixation section 411 The dye dilfusion and fixationsection 411 comprises a chamber 414 having side walls 415 and 416, abottom 417 and a top 418. The side wall 415 is provided with heatingmeans 428e. The heating means may be electrical, steam, or flamesystems, commercially available and operative under the conditions hereemployed, e.g., nature of solvent to be heated, etc. Along the side wall415 is an opening 421 which is located near the upper extent of the sidewall 415. This opening 421 provides ingress into the interior of thechamber 414 of a base material 422, e.'g., floor covering to which a dyeformulation has been applied. Located within the chamber 414 extendingperipherally around the interior walls at a point just below the opening421 in side wall 415 is a series of coils 423 which serve as condensingsurfaces for vapors which are generated within chamber 414. These coils423 establish the upper extent of the vapor zone 427 within chamber 414.

Located directly below said coils 423 is a trough 424 to collect thecondensate from coils 423. The trough 424 is in fluid communication witha storage tank not shown and/or the well 419 supplying liquidvaporizable solvent to the well 419 as well as solvent for preparationof dye formulations.

The interior of the chamber 414 is provided with idler rolls 425 locatedin a manner to direct the base material 422 into chamber 414 in a path426 to maintain the base material 422 within the zone of vapors 427established between the condensing coils 423 and the bottom 417 of thechamber 414. Positioned along the path 426 of the base material 421through zone 427 of chamber 414 are a series of nozzles 428. Thesenozzles 428 are supplied with superheated vapors of a solvent throughheader 428a which is connected to the exterior piping 428b, asuperheater section 428e, a pipe 428d, a fan or blower 428e and a pipe428 which is connected through the side wall 415 of section 411.

The location of the condensing coils 423 is such that above the vaporlevel 427a established thereby is a sub- ,stantially vapor-free zone 429which is essentially quies- 10 cent in nature. This zone 429 extendsacross and above each of the other units 412 and 413.

A series of idler rolls 430 are located within unit 412 to directmaterial 421 into chamber 431 which is the scouring unit 421. Locatedwithin scouring unit 412 chamber 431 are a series of nozzles 432 whichare connected to a pressurized source of rinse liquid. The lower portionof chamber 431 is resignated to hold a quantity of scour liquid 433sufficient to engulf the base material 421 during its passage throughchamber 431. The nozzles are positioned in a manner such that theirforce is directed against the normal flow of liquid down the basematerial thus offsetting to some extent the efiect of cascading createdby liquid flowing downwardly over the heavy nap of the floor coveringcausing the nap to bend with the flow. The chamber 431 has been providedwith a series of condensing coils 434 to condense vapors which might begenerated within chamber 433 and a trough 435 to collect the condensedvapor thus preventing vapors from escaping into zone 429.

Unit 413 is similar in construction to unit 411 but is somewhat of amirror image thereof. Unit 411 provides a means for removing scouringsolvent from the base material and recovering the so-removed solvent.

Other modifications will become apparent to those skilled in the art.

The operation of the apparatus illustrated in the figures isself-evident and is readily seen to permit conducting the novel methodof dyeing hereinbefore described. The dyeing process of the presentinvention has been carried out employing a prototype of the apparatusdescribed in FIG. 4 on a pilot plant scale with good results.

In the operation of the apparatus described hereinabove, the loss ofsolvent was about five (5%) percent of that introduced into theapparatus either in the dye formulation or as vapor and/or scouringliquor.

It is to be understood that when rinsing is not necessary to remove dyeassists, etc., the scouring section 412 and the drying unit 413 need notbe employed. Thus one can dye a fabric satisfactorily in an apparatussuch as illustrated in FIG. 3.

We claim:

1. An improved method for dyeing natural and synthetic textile materialswhich comprises:

(a) contacting said textile material with a dyestuff dissolved ordispersed in at least one organic solvent which is a vehicle for saiddyestufi;

(b) passing said dyestutf wet textile material through a zone of vaporsof a volatile organic solvent, having a boiling point between about 40C. and the softening point of the textile material, which may be thesame or different from said vehicle, said zone being at a temperaturesuflicient to fix the dyestuff; and,

(c) withdrawing from said vapor zone said textile material with said dyefixed therein.

2. The method of claim 1 wherein the textile material is passed throughstep (b) in from about 10 to seconds.

3. The method of claim 2 wherein subsequent to withdrawal of the dyedtextile material from the vapors of step (c) the textile material isscoured with a liquid organic solvent having a boiling point betweenabout 40 C. and the softening point of the textile material, then passedthrough a zone of the vapors of said solvent for a time sufiicient toraise the temperature of the textile to at least the boiling point ofthe solvent to remove the solvent, and finally passing the textilematerial to an atmosphere substantially free of solvent.

4. The method of claim 3 wherein the solvent removed from the textilematerials is recovered by condensing the vapors which form in the vaporzone in excess of those vapors necessary to maintain the zone.

5. The method of claim 1 wherein the organic solvent which is a vehiclefor the dyestuif and the vapors within the vapor zone are the same.

6. The method of claim wherein the organic solvent is a halogenatedorganic solvent.

7. The method of claim 5 wherein subsequent to withdrawal of the dyedtextile material from the vapor zone of step (c) the textile material isscoured with a liquid organic solvent having a boiling point betweenabout 40 C. and the softening point of the textile material, then passedthrough a zone of the vapors of said solvent for a time sufficient toraise the temperature of the textile to at least the boiling point ofthe solvent to remove the solvent, and finally passing the textilematerial to an atmosphere substantially free of solvent.

8. The method of claim 1 wherein at least a part of the organic solventwhich is a vehicle for the dyestufi is different from and boils higherthan the solvent from which the vapors in the vapor zone are generated.

9. The method of claim 8 wherein subsequent to withdrawal of the dyedtextile material from the vapors of step (c) the textile material isscoured with a liquid organic solvent having a boiling point betweenabout 40 C. and the softening point of the textile material, then passedthrough a zone of the vapors of said solvent for a time suflicient toraise the temperature of the textile to at least the boiling point ofthe solvent to remove the solvent, and finally passing the textilematerial to an atmosphere substantially free of solvent.

10. The method of claim 9 wherein the textile material is maintained inthe solvent vapors of step (b) for from 10 to 180 seconds.

11. An improved method for dyeing textile materials which comprises:

(a) contacting said textile material with a dyestufif for said textilematerial, said dyestuff being dissolved or dispersed in at least oneorganic vehicle for said dyestufi, said organic vehicle being selectedfrom at least one of the classes (1) solvents boiling between about 40C. and the decomposition temperature of the dyestuft" or textilematerial whichever is lower,

(2) solvents boiling above the decomposition point of the dyestuffand/or the textile material,

thereby to wet the textile material with said dyestutf and said solvent,

' (b) passing said so-wetted textile material through a zone of vaporsof an organic solvent of the class (a) (1), said zone being maintainedat a temperature sufficient to fix the dyestuif and said zone beingmaintained at a temperature substantially above that at which thetextile material is contacted in step (a);

(c) subsequently introducing the textile material through a liquid bathof solvents of class (a)(1) thereby to remove unfixed dyestuif and anysolvent having a boiling point above that of the solvent of (b), if any,as well as any other solvent-soluble materials which are employed alongwith the dye- Stuff;

(d) passing said so-rinsed textile material through a zone of vapors ofa solvent of class (a) (1) which are at a temperature that the textilematerial is substantially free of all solvents; and

(e) removing the textile material to an atmosphere substantially free ofsolvent and in a dyed state.

12. The method of claim 11 wherein at least a part of the vehicle ofstep (a) and the solvent of the vapor zone of step (b) and the solventof step (c) each is a halogenated hydrocarbon solvent having from 1 to 4carbon atoms and from 2 to 4 halogen atoms having an atomic number from9 to 35, and said vapors in the zone of steps (b) and (d) aresuperheated vapors.

13. The method of claim 11 wherein said organic vehicle and said vaporzone solvent are the same and are selected from the group of halogenatedhydrocarbons having from 1 to 4 carbon atoms and 2 to 4 halogen atomshaving atomic numbers 9 to 35.

14. The method of claim 11 wherein said textile material is in the formof fibers formed in a loose stock, yarn, fabric or carpet.

15. The method of claim 13 wherein said halogenated hydrocarbon isperchloroethylene.

16. The method of claim 13 wherein said halogenated hydrocarbon istrichloroethylene.

17. The method of claim 13 wherein said halogenated hydrocarbon is1,1,l-trichloroethane.

18. The method of claim 13 wherein said halogenated hydrocarbon ismethylene chloride.

19. An improved method for dyeing natural and synthetic textilematerials comprising contacting the material with a dye dissolved ordispersed in an organic solvent, passing the thus wetted fibers througha zone containing Vapors of an organic solvent which boils between about40 C. and below the decomposition point of the dye and the fibers, saidpassage through said zone of vapors being accomplished in between about10 and about seconds, withdrawing the dyed fibers therefrom, scouringexcess dye and non-volatile dye assistants from the fibers and dryingthe fibers.

References Cited UNITED STATES PATENTS 2,274,751 3/1942 Sowter et al.894 X 2,828,180 3/1958 Sertorio- 8-62 2,999,002 9/1961 Dayvault et al.8165 X 3,098,691 7/1963 Pascal 8179 X 3,313,590 4/1967 Delano et al.8-94 X GEORGE F. LESMES, Primary Examiner T. J. HERBERT, 1a., AssistantExaminer U.S. Cl. X.R. 8-174 I mg o UNITED STATES PATENT OFFICE fCERTIFICATE OF CORRECTION Patent No. 3,667 898 Dated 6 June 1972Inventofls) Sylvester Bergman and Ross R. Dawson It is certifiedthat-error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 9, line 10, change "-fnation" to mulation. Q

Column 10, line 5, change "421." to --412-.

line 8, change resignated" to ilesig:r1 ed-.

Signed and sealed this 12th day or December 1972.

(SEAL) Attest:

EDWARD M-.FLETCHER,JR. ROBERT GOTISCHALK Attesting Officer Commissionerof Patents

